Three-product nozzle-type centrifuge



p 7, 19% R. w. HONEYCZHURCH 3,204,868

THREE-PRODUCT NOZ ZLE-TYPE CENTRIFUGE Filed June 6, 1960 3 Sheets-Sheet l llllllllll INVENTOR. 9056/27 14 fio/vz YCHUR c/1 BY dim 42% a Sept. 7, 1965 R. w. HONEYCHURCH 3,204,868

THREE-PRODUCT NOZZLE-TYPE CENTRIFUGE 3 Sheets-Sheet 2 Filed June 6, 1960 ATTO R N EY p 1965 R. w. HONEYCHURCH 3,204,868

THREE-PRODUCT NOZ ZLE-TYPE GENTRIFUGE Filed June 6, 1960 3 Sheets-Sheet 5 INVENTOR ROBERT W. HONEYCHURCH BY Han are %1 ATTORNEY United States Patent 3,204,868 THREE-RODUCT NOZZLE-TYfE CENTRIFUGE Robert W. Honeychurch, Stamford, Conn, assignor to Doric-Oliver Incorporated, Stamford, Comm, a corporation of Delaware Filed June 6, 1960, Ser. No. 34,303 11 Claims. ((11. 233-14) This invention relates to improvements in centrifuges for effecting the separation of a feed mixture or emulsion into overflow liquid fractions of different specific gravities and a third fraction which may be a heavier solids hearing concentrate derived from the centrifugal separation chamber in the rotor bowl of the centrifuge.

Centrifugal machines for this purpose are of the socalled nozzle type, as distinct from the so-called solid bowl construction which latter lack the discharge nozzles for discharging a concentrate. Solid bowls are, therefore, limited to the separation of component liquids of different specific gr-avities by overflow.

More particularly, this invention is concerned with a nozzle-type machine for three-product centrifugal opera- .tion of the respective components of a solids bearing mixture, where solid bearing concentrate discharges from the nozzles provided upon the outer periphery of the separating chamber, while the two liquid fractions of different specific gravities discharge through respective overflow passages. For example, crude oil may thus be separated into an oil fraction, a water fraction, and a concentrate which may consist of water containing solids such as sand and other particles. Other examples of three-product separation that may be advantageously handled in the improved machine, are found in various solvent extraction operation-s wherein the mixture or emulsion may represent .a component system of solvent, water, and spent sludge.

Control liquid, or nozzle discharge material, or both, may be supplied into the rotor bowl to satisfy the nozzle flow requirements as well as for establishing operating balance as between the underflow from the nozzles and the overflows. By these controls it. is possible to regulate the underflow concentration as well as to control location of the respective centrifugal separation zones in the bowl, and also to effect washing of the solids to free them of mother liquor or dissolved values or the like before they discharge from the nozzle means as concentrates. Varying the diameter of at least one of the overflows is another means of influencing the separating operation within the bowl.

This invention has among its objects to provide an improved centrifugal machine for effecting a greatly improved separation of the fractions. The invention, therefore, is directed towards obtaining the fractions at maximum purity, in that contamination of any of the fractions by any of the other fractions is minimized or substantially avoided. More particularly, the object is to provide an improved rotor bowl constructed so as to greatly improve the separation of the two liquid overflows from each other by minimizing or eliminating the possibility of their getting intermingled in the operation of the machine.

Accordingly, the invention provides a rotor bowl construction wherein two overflow liquids being of different specific gravities discharge from respective overflows at opposite ends of the bowl, while solids bearing underflow fraction may discharge from the nozzle-s about mid-way between the relatively constricted end portions of the bowl.

Preferably, the invention is embodied in a rotor bowl of generally double-conical configuration with the narrow ends of the conical end portions thereof pointing in opposite direct-ions. The separating chamber of the bowl is constituted by a hub portion, closing one of the conical end portions of the bowl, 'by an intermediate nozzle-carrying portion of the bowl, and by the other conical end portion which is open to provide a primary overflow. The rotor shaft extends from the hub through the separating chamber and through the primary overflow end of this bowl.

More particularly, the improvements feature a special arrangement of two sets of flow transfer conduits embodied in a rotor bowl. Both sets of conduits are located mutually adjacent in the one conical end portion of the rotor bowl which is directed opposite to the primary overflow, so that the conduit-s pass through the hub portion of the bowl. One set of these transfer conduits preferably comprises an arrangement of divergent inserted influent tubes for passing control liquid from an influent chamber to the region of the discharge nozzles. The other set of transfer conduits is convergent for passing the heavier liquid fraction from an intermediate centrifugal separating zone out into the discharge chamber which preferably surrounds the influent chamber, and from which this heavier secondary overflow fraction may pass out to discharge over an annular dam.

Control or wash liquid, or underflow recirculating from the nozzles, or both, may be supplied into the aforementioned influent chamber of the rotor bowl for delivery through the set of divergent influent tubes to the nozzles.

Any tendency of the overflow fractions to intermingle is obviated by the above arrangement, while loss of overflow liquid into the nozzle discharge product is minimized.

The improved rotor further features an arrangement wherein the convergent eflluent conduits for the secondary overflow pass through the influent chamber in such a manner as to provide recesses in the influent chamber through which the control liquid or the like may pass into the oppositely directed divergent set of tubes.

The improved machine of this invention is advantageously employable in three-product separation operations where, for example only one of the overflowing fractions is of value to be recovered while the other overflow fraction and the underflow may go to waste. In another advantageous application, both overflow fractions are sought to be separated and recovered, whereas the nozzle discharge product may go to waste.

Features of the invention are, therefore, also directed to such applications vas are exemplified respectively by the three-product separating treatment of crude oil, separating the oil from the Water and from sand, and also by the separating treatment of solvent water solids mixtures such as may result for instance from the solvent extraction of a fermentation broth.

Other features and advantages will hereinafter appear.

As this invention may be embodied in several forms without departing from the spirit or essential characteristics thereof, the present embodiment is, therefore illustrative and not restrictive, since the scope of the invention is defined by the appended claims rather than by the description preceding them, and all changes that fall within the metes and bounds of the claims, or equivalents of such metes and bounds, are, therefore, intended to be embraced by the claims.

FIG. 1 is a vertical section through a centrifugal machine including the novel rotor bowl, illustrating particularly the relative arrangement of the convergent and the divergent sets of flow transfer conduits;

FIG. 1a shows a different manner of feed introduction;

FIG. 2 is an enlarged detail sectional view taken on lines 2-2 further illustrating the arrangement of the two sets of opposedly directed flow transfer conduits;

FIG. 3 is an enlarged view of the rotor bowl showing more clearly the details thereof;

FIG. 4 is a detail sectional view taken on lines 44 looking in a direction opposite to a similar section 22 shown in FIG. 2;

FIG. 4a shows an example of flexible sealing means associated with the primary overflow;

FIG. 5 is a diagrammatic view of the embodiment of FIG. 1 along with pipes and valves associated with the housing of the centrifuge for illustrating various modalities of operation;

FIG. 6 is a diagrammatic view of the same rotor bowl mounted in a simplified housing arranged for the combined discharge of two of the three separated fractions, with valve pipe connections for variously operating the same.

A centrifuge machine embodying the invention exemplified in FIGS. 1 to 4 comprises a rotor 10 operating in a stationary housing 11. Mounted on top of the housing are means from which the rotor shaft 12 is suspended and mounted for rotation. The means of rotor support being well known are herein indicated only by the fragmentary showing of a top bracket structure 13 carried by the housing,

The rotor embodying features of this invention comprises a so-called rotor bowl of generally double-conical configuration having constricted ends 14 and 15 for delivering respective separated liquid fractions as primary overflow 14a and a secondary overflow 15a (FIGURE 3). This configuration of the bowl, therefore, also comprises an intermediate portion 17 delivering a third fraction or concentrate also termed underflow 17a through well known discharge nozzles 18 mounted in this outer peripheral portion of the bowl. In the FIG. 1 example, feed mixture or emulsion with solids may enter the rotor 10 through the primary overflow end thereof while control liquid or recirculating underflow may enter the rotor through the opposite end from an injection nozzle device 20 including return flow regulating means 20a.

More particularly, the construction of the improved rotor bowl in this embodiment comprises a hub portion 21 (FIGURE 3) fixedto shaft 12 and shown to be integral with one trunco-conical end portion 22 of the bowl. The wide end of this end portion is formed with a cylindircal rim 23 preferably formed with an inner peripheral race or groove 24 communicating with the discharge nozzles 18 mounted in the rim. An opposite tnmco-conical end portion 24a of the bowl has its wide end tightly, although detachably, connected to the wide end of the conical end portion 22, being fitted into the rim 23 and secured thereto as by well-known securing means such as a spreader ring indicated at 25. At its narrow end the conical end portion 24a of the rotor bowl terminates in a cylindrical portion 26 which in turn provides an overflow lip 27 for the aforementioned overflow 14a.

The hub portion together with the two trunco-conical end portions of the bowl constitutes a centrifugal separating chamber 28 wherein there is mounted a feed inlet member 29 comprising a substantially cylindrical outer end portion 30 and a conical or flaring inner end portion 31 seated upon the correspondingly conical face 32 of the hub portion and held in place as at 31a by pressure contact with the conical end portion 24a. of the bowl. The feed member 29 thus provides around the shaft a feed inlet passage 33 into which may extend an annular feed supply conduit 34 surrounding the shaft, formed by concentric tubes 34a and 34b. Feed mixture from this supply conduit passes through divergent feed passages 35 into the separating chamber which may have perforated tubes 36, for distributing the feed mixture, cooperatively associated with a stack of separating discs 37. The function of these discs is well known in that they tend to separate and reject fine solids or other rela tively heavier component materials carried by the light liquid fraction passing through the interstices between the discs for discharge through the primary overflow 14a.

and in substantially the same conical alignment.

Detachably connected to the hub portion is a compartmented complementary construction 38 constituting a part of the rotor bowl, which provides an influent chamber 39 for receiving control liquid or returning underflow material, and surrounding it is an annular discharge chamber 40 collecting and discharging the secondary liquid fraction as over a ring dam member 41. This complementary construction comprises an annular member 42 preferably shaped to comprise a short cylindrical outer end portion 43 and a trunco-conical or flaring inner end portion 44 detachably connected to the hub for instance by means of a thread connection 45. The ring darn member 41 is detachably held as by a retainer ring 46 threaded onto the outer end portion 43 of this construction.

An annular partition 47 extends inwardly of the annular member 42, defining the just mentioned influent and effluent chambers 39 and 40 respectively. Partition 47 as here illustrated comprises a trunco-conical base portion 48 having its narrow end directed towards the hub, and a trunco-conical free end portion 49 extending from the narrow end of the base portion in a direction away from the hub.

A special arrangement of flow transfer conduit means is provided to carry control liquid or recirculating underflow from the influent chamber 39 through the hub portion inwardly to the region of the nozzles, and to carry secondary liquid fraction from an intermediate separating zone through the hub portion outwardly into the effluent chamber 40 for discharge through the secondary overflow.

In the embodiment herein illustrating the invention, this transfer conduit arrangement comprises a set of divergent influent tubes 50, and a set of convergent effluent tubes 51, both sets of tubes being arranged around the rotor axis, preferably adjacent to each other, as well as adjacent to the wall of the respective conical portion of the bowl. In a practical embodiment, the respective divergent and convergent tubes are arranged in alternatiolii, T e convergent efliuent tubes 51 of this embodiment extend through the influent chamber 39 in such a manner as to constitute between them recesses 52 (in FIG. 4) through which the control liquid or the like may reach and enter into the divergent influent tubes 50. Radial vanes 53 are provided in the influent chamber 39, more clearly shown in FIG. 2 for urging control liquid or returning underflow into the divergent influent tubes 50.

The housing in the embodiment of FIG. 1 has separate discharge outlets for the three separated fractions and accordingly has a top receiving chamber 54 provided with an outlet 55 for the primary overflow, a bottom receiving chamber 56 provided with an outlet 57 for the secondary overflow, and an intermediate volute chamber 58 with outlet 59 for discharging underflow material from the nozzles. In the embodiment shown, the housing is subdivided into structural sections which comprise a cylindrical section 60 formed with an annular partition 61 and also with the outlet 55, a top cover portion 62 fastened to the upper end of the cylindrical section and carrying the aforementioned bracket structure 13 for supporting the rotor, a volute section 63 fastened to the lower end of the cylindrical section and formed with the outlet 59, and a conical bottom section 64 fastened to the lower end of the volute section and formed with the outlet 57. Moreover, this embodiment shows an external return conduit 65 for recirculating underflow from the nozzles back into the rotor through the injection device 20, 20a, with an underflow discharge control valve 66 operable to control the recirculation rate and thus the concentration of the underflow. Additional control liquid or wash water or the like may be introduced into the underflow return circuit as by means of a valve 67. The return conduit 65 has an additional valve 68 whereby recirculation therethrough may be interrupted while underflow discharge through valve 66 and the introduction of the control liquid through valve 67 may be operated individually. The separation of the intermediate fraction from the light fraction may be aided by separating discs 37 the function of which of itself is well known in the art.

In the operation of the machine as illustrated in FIG- URES 1 to 4, the feed mixture or emulsion enters the rotor through the stationary annular feed conduit 34 which extends into the feed inlet passage '33 within the rotor, whence the mixture passes on through downwardly divergent feed passages 35 into the separating chamber 28 of the rotor bowl. Rotation of the bowl will cause separation of the components of the mixture, for example, into three fractions of different specific gravities, namely a sludge fraction discharging through the nozzles from the outer peripheral zone of the separating chamber, an intermediate liquid fraction passing from the separating chamber through convergent tubes 51 into the annular discharge chamber 40 and out at the bottom over ring dam 41 as secondary overflow, and finally a light liquid fraction discharging from the overflow lip 27 at the top. Meanwhile, control liquid or wash water or recirculating underflow from nozzle discharge may be injected continuously from the bottom into the infiuent chamber 39 where the pumping vanes 53 will insure that this liquid enters the divergent transfer tubes 50 to introduce the heavy fraction or sludge back into the region of the nozzles. Adjusting the rate of sludge draw-off at valve 66 will correspondingly influence the concentration of the underflow, in that a decrease in the rate of drawoff will increase the concentration. Wash liquid may be added to the sludge return, or wash liquid may be used alone. However, it will be understood that the nozzle flow requirements may be satisfied by recirculating nozzle discharge or by the addition of wash liquid from another source, to establish a suitable interface for maintaining light fraction separation.

Such various modes of operation, as exemplified in the improved three-product nozzle type machine will be readily understood from the diagrammatic FIG. 5 reflecting the embodiment illustrated in FIGURES 1 to 4, with addition of valves and pipes for executing various modes of operation. Here again, feed mixture 69 enters a rotor 70 and through passages 71 reaches the separating chamber 72. Consequently, a light liquid fraction 73 overflows from the top end of the rotor bowl and passes from the housing 74 as indicated by the arrow 75. An intermediate liquid fraction discharges through convergent passages 76 into the discharge chamber 77 and over a ring dam 78 as secondary overflow 79 passing from the housing as indicated by the arrow 80 into a discharge pipe 80a. The heavy fraction or sludge discharges through nozzles 81 as indicated by arrows 82 and out of the housing as at 83 into a discharge pipe 84. By operating a discharge valve 84a and manipulating the valve 86, a portion of the underflow may be recirculated through pipe 85 and valve 86 and then through pipe 87 leading through the bottom of the housing back into the rotor chamber 88. Arrows 89 and 90 indicate how the underflow then passes from the chamber 88 centrifugally through passages 91 and divergent conduits 92 into the region of the discharge openings or nozzles 81. Secondary overflow such as water, discharging at 80 may be disposed of through valve 94, although at least a portion thereof may be returned through a valve 95 into the sludge return pipe 87. Also, auxiliary control liquid or water 95a may be introduced through valve 96 into the sludge return pipe 87. By still another mode of operation, valve 86 may be closed to cut off underflow return if desired, while the primary overflow 75 and secondary overflows 80 may be kept discharging separately. Also, the valve 95 may be kept closed, while auxiliary Wash liquid 95a or the like enters through open valve 96.

According to the diagrammatic FIGURE 6, the rotor 97 is similar to the one shown in the diagrammatic FIG- URE 5, and will, therefore, similarly effect a three-product separation. The housing 98, however, differs in that it has provision for separately discharging only the light or primary overflow fraction as at 99 whereas the nozzle discharge product or underflow 100 will join the secondary underflow 101 in the wide bottom portion 102 of the housing. The mixture of these two fractions discharges from the housing into a receiver tank 103 from where a pump 104 may send at least part of this mixture through valves 105 and 106 back into the rotor 97, while another portion may discharge from the system as through a discharge valve 107. Provision is further made for adding auxiliary liquid or control or wash liquid into the tank as through valve 108, or else into the pump delivery pipe as through valve 109, or through valve 110 into the partial stream that enters the housing through valve 106. Flow control devices 111 and 112 may be provided in the tank for automatically actuating the discharge valve 107, so that the level of the mixture in the tank will be maintained between the upper and the lower limits L and L respectively. The contents of this tank may be reduced or drained through a valve 113 provided in a discharge pipe 114.

From the foregoing it will be seen that the invention provides an improved centrifuge machine for effecting improved separation at high purity as by the two overflows discharging from the respective ends of the rotor, and separated from each other by the interposed underflow discharging at a much higher peripheral speed some where midway between these overflows.

The improved rotor construction not only makes a highly effective separation of the three fractions in the separating chamber of the bowl, but also discourages and prevents any contamination among the tw overflow fractions themselves, such as might otherwise be caused by windage effects within the space between the rotor and the housing because of the relatively high outer peripheral speed of the nozzle section of the rotor. The purity of the respective overflows is thus maintained to a high degree by the operation of this improved machine, since any small amount of overflow liquid that might stray into the space between the rotor and the housing is necessarily trapped in the underflow fraction from which it is recoverable as in a supplemental treatment step here not shown.

Structurally the machine is of great simplicity, easy to inspect and to assemble. For example (see FIGS. 1 and 3) the inserted transfer tubes 50 and 51 are in the form of simple straight tubes having partial extensions 50a and 51a respectively. These tubes are held in proper operating position by reason of the centrifugal force tending to push them towards the nozzle section where the respective extensions 50a and 510 have abutting contact with the nozzle section of the bowl. In case of disassembly, inspection and cleaning of the machine, conveniently first the tubes 51 are withdrawn through discharge chamber 40, whereupon the complementary construction 38 may be detached or unscrewed from the hub portion of the bowl. With the hub portion thus eX- posed, the other tubes 50 are then accessible for withdrawal. To attain access to the separating chamber, only the spreader ring 25 need be removed, whereupon the conical end portion 24a of the bowl can be lifted off its base, whereby the vertical feed passages 36 and the separating discs 37 as well as the nozzles 18 in the bowl became accessible even as the shaft may remain connected to the hub.

It will be understood that each of the elements described above, or two or more together, may also find a useful application in other types of centrifuge machines differing from the ones described above.

While the invention has been illustrated and described as embodied in a nozzle type centrifuge machine for three-product separation, it is not intended to be limited to the details shown, since various modifications and structural changes may be made without departing in any way from the spirit of the present invention.

Furthermore, while the invention has exemplary application to three-product separation in one instance of crude oil into clean oil, water, and solids carrying underflow, and in another instance of a fermentation broth into solvent, water, and spent sludge, it should be understood that the invention is not limited thereto, in that other applications are conceivable whereby the features and advantages of the invention may be utilized.

Also, the feed mixture may contain solids at times, but not other times, yet the invention may be applied advantageously in both instances. Hence, the invention is not to be considered as limited in this respect. For example, the machine may be employed to advantage for the separation treatment of crude .oil in a locality where solids are carried by the oil, as well as in other localities where the crude oil may be solids-free.

While the divergent tubes 50 have been described as delivering the control liquid in the region of the nozzles, it should be understood that a preferred arrangement of the tubes is to have the respective points of delivery disposed about midway between respective nozzles.

Furthermore, the control liquid as herein understood may comprise any kind of liquid passing or returning through the divergent tubes 51, for example wash liquor or recirculating underflow from the nozzles.

Furthermore, in FIG. In there is to be noted that the vertical feed distributing tubes 36a are located outwardly adjacent to the periphery of the separating discs 37a, instead of having the tubes penetrate the discs in accordance with prior art arrangements. An advantageous effect is attainable by the arrangement according to FIG. 1a, for example in connection with the aforementioned crude oil separation operation, when wax from the oil may accumulate in an indeterminate intermediate zone in the separating chamber and lead to wax deposits on the discs clogging the narrow interstices therebetween. The advantage of the arrangement according to FIG. l'a lies in fact that the feed streams emanating laterally from the tubes 36a which are slotted for that purpose, will tend to disperse the wax causing it to go with the oil to the primary overflow, and thereby avoiding wax deposits between the discs.

A feature shown in FIG. 4a for further discouraging any intermingling of the separated fractions in the machine lies in the provision at the primary overflow of an annular sealing element consisting of a flexible tough material such as plastic, for example, a ring member M of Teflon is secured to the overflow end of the rotor as by a threaded retainer ring G, arranged to establish sealing relationship with the stationary part 61 of the housing during the rotation of the rotor, substantially as by tangential contact A.

Reverting to the diagrammatic operating arrangement of FIG. 6, and considering the example of crude oil separation therein, it will be noted that variations of the liquid level in the receiver tank 103 are utilized by the float controlled devices 111 and 112 to automatically control the rate of supply into the rotor bowl of the amount of heavy phase liquid or water that may be needed as dictated by varying degrees of deficiency in the water content in the crude. Thus, the control arrangement acts to correctively change the supply of water to the discharge nozzles needed to maintain a peripheral separating zone of water as a safety seal in the bowl preventing the escape of oil or light fraction phase as underflow.

It will be seen with respect to the operating arrangement of FIG. 6 that the response of the control devices thus depends upon variations in the combined volume of underflow and heavy phase overflow or water discharging into the receiver tank, which variations in turn depend upon the flow rate changes in the overflow since the designed flow rate through the nozzles should remain relatively constant. Corrective efiects are attained by the throttling of the control of valve 107 as effected by the automatic controls and indicated by the dotted lines 8 c and c connecting the valve with the control devices 111 and 112.

Similar control eflects are attainable by means of a similar control arrangement in connection with the embodiment of FIG. 5, but not illustrated, which may utilize directly the changes in the water overflow rate itself as a criterion for effecting the corrections. For example, if the feed to the centrifuge represents a mixture of light phase liquid, of heavy phase liquid, and of solids, as in crude oil, then with a varying content of heavy phase of water this control arrangement will maintain the heavy phase or peripheral water seal in the bowl intact regardless of the variations of the water phase in the feed. In this example, the control effects are obtainable by way of measuring the discharge of the heavy phase overflow liquid through the secondary overflow into a receiver tank, and using the variations in the secondary overflow rate as a criterion for controlling or throttling the underflow draw-01f rate through valve 84a and thus regulating the underflow recirculation rate..

Such a control arrangement may be implemented in various ways and by means of a variety of instrumentations. For example, the secondary overflow liquid may be detained in a receiver tank equipped with suitable floatactuated proportional control devices which may regulate the underflow draw-oft" valve 84a automatically in proportion to changes in the liquid content in the feed, the tank also being provided with adjustable discharge or control devices or other suitable discharge means to allow for discharging a substantially constant basic volume of draw-off liquid from the tank.

Thus, in case the heavy phase or water content in the crude oil diminishes, then the control devices will act to throttle down the draw-off valve 84a sufficiently to maintain the inventory of heavy phase or water in the system necessary for insuring against the escape of light phase or oil through the nozzles and the underflow. Should the heavy phase or water in turn become excessive in the feed, such an occurrence would show up in an increased rate of secondary overflow which in turn through the control devices would open the draw-off valve 84a accordingly.

Still, in connection with the FIG. 5 embodiment, the control devices may also operate in response to extreme deficiency of water in the feed or otherwise, to admit water from an auxiliary supply into the centrifugal system, namely through valve 96 which may be regulated proportionately from the control devices.

In addition, the arrangement shown in FIG. 6 can also be modified so as to provide for the removal of the solids prior to the reinjection of the carrying liquor back into the rotor. These solids can be removed as by means of a trap. Preferably, pump 104 will 'pass this stream through a hydrocyclone (not shown) where the solids will either be removed into a special collecting chamber or be removed continuously from the system. The overflow from the hydrocyclone will comprise the reinjection stream for the rotor and also the draw-off from the system. If the solids are but a small fraction of the total stream they may be removed by means of an intermittently dischargeable grit-pot system, whereas if they are in a greater fraction they may be removed continuously as above indicated. If the solids are not detrimental to the functioning of the equipment or the process, they need not be removed as a separate and concentrated fraction as by the interposed cyclone means or the like, but may be allowed to remain in the underflow circuit.

I claim:

1. A centrifuge rotor comprising conically-shaped end portions with their wide ends adjacent to each other to constitute an annular separating chamber, passage means for introducing a mixture into said separating chamber,

primary overflow means on one of said conically-shaped end portions for centrifugally discharging primary overflow, discharge nozzles mounted upon the outer periphery of the separating chamber for the discharge of centrifugally separated underflow therefrom, a hub portion constituting the outer end of the other conical end portion, a rotor shaft extending from said hub portion centrally through said primary overflow, a complementary compartmented construction detachably connected to said hub portion and providing an influent chamber adjacent to said hub portion and to said separating chamber as well as providing an annular discharge chamber adjacent to said influent chamber and having an annular dam member for centrifugally discharging secondary overflow, a plurality of divergent influent conduits spaced around the rotor axis and leading from said influent chamber through said hub portion into the region of said nozzles, and a plurality of convergent eflluent conduits also spaced around the rotor axis leading from an intermediate centrifugal separating zone through said hub portion into said annular discharge chamber for discharging secondary overflow over said dam, said divergent conduits and said convergent conduits being arranged in alternation.

2. A centrifuge rotor according to claim 1, wherein said convergent conduits comprise tubular elements extending from said annular eflluent chamber through said influent chamber.

3. In a centrifuge machine the combination which comprises a rotor having conically-shaped end portions with their wide ends adjacent to each other to constitute an annular separating chamber, passage means for feeding a mixture into said separating chamber, primary overflow means on one of said conically-shaped end portions, the narrow end of the other end portion being closed, discharge nozzles mounted upon the outer periphery of the separating chamber for the discharge of centrifugally separated underflow therefrom, a rotor shaft extending from the narrow end of the other conically shaped end portion centrally through said primary overflow means, an annular influent chamber adjacent to said separating chamber opposite to said primary overflow means, an annular discharge chamber adjacent to said influent chamber provided with an annular overflow darn for secondary overflow, a plurality of divergent influent conduits disposed around the rotor axis and leading from said influent chamber into the region of said nozzles, a plurality of convergent effluent conduits disposed around the rotor axis leading from an intermediate centrifugal separating zone into said annular discharge chamber for discharging secondary overflow, said divergent conduits being arranged in alternation with said convergent conduits; and a housing wherein said rotor is mounted for rotation by said rotor shaft, said housing having one end portion constructed to provide for separately discharging said primary overflow, and having the opposite end portion constructed to provide a combined receiving chamber for both said underflow from the nozzles and said secondary overflow, and outlet means discharging the mixture of said flows, and underflow return inlet means associated with said annular influent chamber for supplying underflow material thereto.

4. A centrifuge rotor comprising conically shaped end portions with their wide ends adjacent to each other to constitute an annular separating chamber, primary overflow means on one of said conical shaped end portions for centrifugally discharging primary overflow, the narrow end of the other end portion being closed, discharge nozzles mounted upon the outer periphery of the separating chamber for the discharge of centrifugally separated underflow therefrom, a rotor shaft extending from the narrow end of said other conically shaped end portion centrally through said primary overflow, passage means for introducing a feed mixture into said separating chamber, an influent chamber adjacent to said separating chamber and opposite to said primary overflow means, an annular discharge chamber adjacent to said influent chamber and having an annular dam member for centrifugally discharging secondary overflow, a plurality of divergent influent conduits spaced around the rotor axis and leading from said influent chamber through the narrow end of said other conically shaped end portion into the region of said nozzles, and a plurality of convergent eflluent conduits also spaced around the rotor axis and leading from an intermediate centrifugal separating zone in said separating chamber through said narrow end of the other conically shaped end portion to said annular discharge chamber for discharging secondary overflow over said dam, said divergent conduits and said convergent conduits being arranged in alternation.

5. The centrifuge rotor according to claim 4, wherein a set of perforated feed distributing tubes connected to said feed passage means are located in the separating chamber arranged around the rotor axis and substantially parallel thereto, and a stack of separating discs concentric with the rotor axis is located within the space between said axis and said distributing tubes.

6. The centrifuge according to claim 4, wherein said divergent conduits and said convergent conduits are substantially in conical alignment with respect to one another.

7. A centrifuge rotor comprising conically shaped end portions with their wide ends adjacent to each other to constitute an annular separating chamber, passage means for feeding a mixture into said separating chamber, primary overflow means on one of said conically shaped end portions for centrifugally discharging primary overflow, discharge nozzles mounted upon the outer periphery of the separating chamber for discharge of centrifugally separated underflow therefrom, a hub portion closing the outer end of the other conical end portion, a rotor shaft extending from said hub portion centrally through said primary overflow, a generally annular complementary construction having a peripheral main wall with means for connecting the same to said hub portion, and having a partition wall extending integrally from said main wall inwardly and formed with a central axially outwardly extending inlet portion, and having inwardly extending radial vanes, said partition wall inwardly defining an influent chamber adjacent to said hub portion, and outwardly defining an annular discharge chamber concentrically surrounding said inlet portion, an annular dam member attached to the free end of said main Wall for discharging secondary overflow, a plurality of divergent influent conduits leading from said influent chamber through said hub portion to the region of said nozzles, and a plurality of convergent eflluent conduits leading from an intermediate centrifugal separating zone in the separating chamber through said hub portion into said annular discharge chamber for discharging secondary overflow over said darn.

8. A centrifuge rotor comprising conically shaped end portions with their wide ends adjacent to each other to constitute an annular separating chamber, passage means for feeding mixture into said separating chamber, primary overflow means on one of said conically shaped end portions for centrifugally discharging primary overflow, discharge nozzles mounted upon the outer periphery of the separating chamber for the discharge of centrifugally separated underflow therefrom, a hub portion closing the outer end of the other conical end portion, a rotor shaft extending from said hub portion centrally through said primary overflow, a generally annular complementary construction having a peripheral main wall consisting of a trunco-conical end portion with means for connecting the wide end thereof to said hub portion concentrically therewith, and of a cylindrical outer end portion extending from the narrow end of said trunco-conical portion, said construction further having a partition wall extending from said main wall inwardly and formed With a central axially outwardly extending inlet portion and having radial vanes extending inwardly at least partially from said trunco-conical portion, said partition wall inwardly defining an influent chamber adjacent to said hub portion, and outwardly defining an annular discharge chamber concentrically surrounding said inlet portion, an annular dam member attached to the free end of said main wall for discharging secondary overflow, a plurality of divergent influent conduits leading from said influent chamber through said hub portion to the region of said nozzles, and a plurality of convergent effluent conduits leading from an intermediate centrifugal separation zone in the separating chamber through said hub portion into said annular discharge chamber for discharging secondary overflow over said dam.

9. The centrifuge rotor according to claim 8, wherein said hub portion has a peripheral internal thread and said trunco-conical end portion is externally threaded at its wide end for thread connection with said hub portion.

10. The centrifuge rotor according to claim 8, wherein said convergent conduits as well as said divergent conduits comprise inserted tubular elements.

11. In a centrifuge the combination which comprises a centrifuge rotor having conically shaped end portions with their wide ends adjacent to each other to constitute an annular separating chamber, passage means for feeding a mixture into said separating chamber, primary overflow means on one of said conically shaped end portions, discharge nozzles mounted upon the outer periphery of the separating chamber for the discharge of centrifugally separated underflow therefrom, a hub portion closing the narrow end of the other conically shaped end portion, a rotor shaft extending from said hub portion through said primary overflow means, an influent chamber outwardly adjacent to said hub portion, an annular discharge chamber adjacent to and concentric with said influent chamber and provided with an annular overflow dam for secondary overflow, a plurality of divergent influent conduits disposed around the rotor axis and leading from said influent chamber through said hub portion into the region of said nozzles, a plurality of convergent effluent conduits leading from an intermediate centrifugal separating zone in said separating chamber through said hub portion into said annular discharge chamber for discharging secondary overflow, a housing wherein said rotor is mounted for rotation by said shaft and having an annular partition means surrounding said one end portion adjacent to said primary overflow means in peripherally spaced relationship therewith; and annular sealing means effective substantially between said primary overflow means and said 12 partition means, comprising an annular sealing lip member of flexible material having an inner peripheral edge portion fastened to said rotor and an outer peripheral edge portion, the outer edge portion having sliding contact with said partition means in a plane extending substantially transverse of the rotor axis.

References Cited by the Examiner UNITED STATES PATENTS 521,043 6/94 Ponten 233-46 1,008,896 11/11 Fisher 233-35 X 1,277,676 9/18 Wright 233-45 1,362,105 12/20 Joseph 252-349 1,649,095 11/27 Brewster 233-14 1,923,454 8/33 Peltzer et a1. 233-14 1,923,455 8/33 Peltzer et a1. 127-69 1,945,786 2/34 Peltzer et a1. 233-28 2,160,140 5/39 Hapgood.

2,301,109 11/42 Clayton 233-29 X 2,417,747 3/47 Flowers 233-46 X 2,458,431 1/49 Schlenz -104 2,500,100 3/50 Strezynski 233-28 2,628,021 2/53 Staaff 233-14 2,697,061 12/54 Harris et a1. 195-1 2,698,303 12/54 Blair et'al. 252-349 2,779,536 1/57 Pomeroy 233-14 X 2,928,592 3/60 Johnson 233-46 2,958,461 11/60 Peltzer 233-47 X 2,973,896 3/61 Peltzer 233-19 3,036,760 5/62 Halbach 233-46 3,073,516 1/63 'Glasson 233-28 3,080,108 3/63 Jacobson 233-14 FOREIGN PATENTS 617,704 8/35 Germany.

OTHER REFERENCES German printed application No. 1,059,841, June 18, 1959.

HARRY B. THORNTON, Primary Examiner.

HERBERT L. MARTIN, GEORGE D. MITCHELL,

ROBERT F. BURNETT, EUGENE F. BLANCHARD,

Examiners. 

1. A CENTRIFUGE ROTOR COMPRISING CONICALLY-SHAPED END PORTIONS WITH THEIR WIDE ENDS ADJACENT TO EACH OTHER TO CONSTITUTE AN ANNULAR SEPARATING CHAMBER, PASSAGE MEANS FOR INTRODUCING A MIXTURE INTO SAID SEPARATING CHAMBER PRIMARY OVERFLOW MEANS ON ONE OF SAID CONICALLY-SHAPED END PORTIONS FOR CENTRIFUGALLY DISCHARGING PRIMARY OVERFLOW, DISCHARGE NOZZLES MOUNTED UPON THE OUTER PERIPHERY OF THE SEPARATING CHAMBER FOR THE DISCHARGE OF CENTRIFUGALLY SEPARATED UNDERFLOW THEREFROM, A HUB PORTION CONSTITUTING THE OUTER END OF THE OTHER CONICAL END PORTION, A ROTOR SHAFT EXTENDING FROM SAID HUB KPORTION CENTRALLY THROUGH SAID PRIMARY OVERFLOW, A COMPLEMENTARY COMPARTMENTED CONSTRUCTION DETACHABLY CONNECTED TO SAID HUB PORTION AND PROVIDING AN INFLUENT CHAMBER ADJACENT TO SAID HUB PORTION AND TO SAID SEPARATING CHAMBER AS WELL AS PROVIDING AN ANNULAR DISCHARGE CHAMBER ADJACENT TO SAID INFLUENT CHAMBER AND HAVING AN ANNULAR DAM MEMBER FOR CENTRIFUGALLY DISCHARGING SECONDARY OVERFLOW A PLURALITY OF DIVERGENT INFLUENT CONDUITS SPACED AROUND THE ROTOR AXIS AND LEADING FROM SAID INFLUENT CHAMBER THROUGH SAID HUB PORTION INTO THE REGION OF SAID NOZZLES, AND A PLURALITY OF CONVERGENT EFFLUENT CONDUITS ALSO SPACED AROUND THE ROTOR AXIS LEADING FROM AN INTERMEDIATE CENTRIFUGAL SEPARATING ZONE THROUGH SAID HUB PORTION INTO SAID ANNULAR DISCHARGE CHAMBER FOR DISCHARGING SECONDARY OVERFLOW OVER SAID DAM, SAID DIVERGENT CONDUITS AND SAID CONVERGENT CONDUITS BEING ARRANGED IN ALTERNATION. 